1. Raise 10666369614354225120 to 16479139101483902597. 2. Take the result and divide by?

... 18074899840695706733.
3. Take the rest of that division.
4. Encode it to hex (remember, always uppercase!)
5. Add the dashes and there you go! That's the key!
If you want to check if you're right in the right track, here's part of the key:

F__-_C__-D__3-58__